TOU rates charge more when the grid is strained—often late afternoon and evening. Solar produces most at midday. Batteries bridge that gap by shifting solar into your peak window.
TOU is a pricing signal. Electricity costs more when demand is high (and/or clean generation is scarce) and less when the grid is comfortable. For many customers, the most painful window is evening—exactly when solar production drops.
Southern California Edison lists plan details on its TOU page: SCE TOU plans.
MIDDAY: Solar high | Home use moderate | Price often lower EVENING: Solar low | Home use high | Price often highest Goal: store midday solar → use it in the expensive window
This is why solar alone can feel underwhelming under modern TOU + Net Billing: you export when it’s cheap and import when it’s expensive.
The “best” settings depend on your utility, your plan, and your lifestyle loads. We tune for real outcomes, not screenshots.
Many commercial bills include kW demand charges. A single short spike can raise the bill for the entire month. Storage can discharge during spikes to cap your kW peak (“peak shaving”), often producing savings solar alone cannot.
For commercial, we model both: (1) energy shifting (kWh) and (2) peak shaving (kW). If you ignore demand charges, you can badly mis-predict ROI.
Start with your target “peak window” and your average load during that window.
“Usable energy” is not the same as “nameplate.” Real designs include reserve, efficiency, and operating limits.
Exporting midday and buying back at night is usually the hard way.
If you want whole-home behavior, you need enough kW to carry the real loads.
Backup and TOU performance depends on what you actually run during peak/outage.
Winter solar is lower. Off-grid and heavy backup goals must be winter-proof.
Want a TOU-first design? Send us: address, latest electric bill, and panel/roof photos. Tell us if you want “TOU savings only,” “TOU + backup,” or “off-grid capable.”